Phenomenological analysis of nucleon strangeness and meson-nucleon sigma terms

Abstract

We calculate the nucleon strangeness $y_N$ in the chiral quark model and the meson cloud model. With the internal relation between the sigma term of $π$$N$ ($σ_{πN}$) and $y_N$, we present the results of $σ_{πN}$ in these two models. Our calculations show that $y_N$ from the chiral quark model is significant larger than that from the meson cloud model, whereas the difference of $σ_{πN}$ between the two models is relatively small. We also present the results of $σ_{K N}$ and $σ_{ηN}$, which could be determined by $σ_{πN}$ and $y_N$ from their definition in the current algebra, and find that these two physical parameters are quite sensitive to $y_N$. The results indicate the necessity to restrict the parameters of the two models from more precision measurements.

13 latex pages, no figure, to appear in PRD